91988725 has 24 divisors (see below), whose sum is σ = 118820520. Its totient is φ = 70560000.

The previous prime is 91988719. The next prime is 91988737. The reversal of 91988725 is 52788919.

It can be written as a sum of positive squares in 12 ways, for example, as 34562641 + 57426084 = 5879^2 + 7578^2 .

It is not a de Polignac number, because 91988725 - 2⁹ = 91988213 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 130875 + ... + 131575.

It is an arithmetic number, because the mean of its divisors is an integer number (4950855).

Almost surely, 2^91988725 is an apocalyptic number.

It is an amenable number.

91988725 is a deficient number, since it is larger than the sum of its proper divisors (26831795).

91988725 is a wasteful number, since it uses less digits than its factorization.

91988725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 921 (or 916 counting only the distinct ones).

The product of its digits is 362880, while the sum is 49.

The square root of 91988725 is about 9591.0752786119. The cubic root of 91988725 is about 451.4173009896.

The spelling of 91988725 in words is "ninety-one million, nine hundred eighty-eight thousand, seven hundred twenty-five".